It is common to arrange subsea wells in protective subsea well templates with a plurality of well slots. For instance, the template can comprise four well slots, wherein two slots are arranged on each side of a manifold arranged in between. In order to have access to well equipment, such as the Xmas trees, hatches are arranged above the slots, which can be pivoted or lifted away.
Such a template is shown in the accompanying FIG. 1, illustrating a template with four well slots and pivotable hatches that are suspended to a robust framework. The top of the template fluctuates with the top cover of a manifold arranged between the two pairs of well slots. For the discussion here and further below, the manifold is said to have a longitudinal axis being parallel to the lines between the two well slots in each pair of slots (being on separate sides of the manifold).
The vertical sides of the template are open for access to the Xmas trees with an ROV, through openings below the upper frame bar. With the shown template, an ROV can access the Xmas tree from two sides, namely from the side being opposite of the side facing the manifold and the side facing the directions parallel to the longitudinal axis of the manifold.
The hatches pivot about a pivot axis being perpendicular to the longitudinal axis of the manifold. Thus, when a hatch is in an opened position, the ROV will preferably access a Xmas tree from the side being opposite of the manifold in order to avoid any interference with the hatch.
When the manifold is being lowered down into the template, all hatches will preferably be in an open position in order to avoid collision with the manifold. One should note that the upper framework needs to be dimensioned to make space for the manifold when it is being lowered or pulled up.
Patent publication NO177647 describes another protective structure for subsea equipment. The structure has a robust framework on top of which are arranged a plurality of pivotable hatches.
Another embodiment of a protective device for subsea installations is described in international patent application WO 03044316. This device has a top cover with a lattice, and four inclined and latticed side covers that extend up to the top of the device from a lower position. The side covers are hinged at the lower position, enabling them to pivot out from the device to an open position.
The object of the present invention is to provide a subsea well template which can accommodate a manifold and with a plurality of well slots, which template combines efficient protection of the subsea equipment inside while providing efficient operation access, such as for an ROV.